JPS63112569A - Dihydrophenazine compound - Google Patents

Abstract

NEW MATERIAL:A dihydrophenazine compound shown by the formula (R<1> is aryl containing electron attractive substituent group or alkyl containing electron attractive substituent group; R<2> and R<6> are lower alkyl; R<3> is aryl or alkyl; R<4> and R<5> are aryl or lower alkyl). EXAMPLE:3-Amino-diethylamino-5-phenyl-10-(2-trifluoromethylbenzoyl)-5, 10-dihy drophenazine. USE:Useful as a thermally image forming compound of oxidation coloring type. By combining with zinc nitrate, aluminum nitrate, etc., to color thermally and by irritating thermally gives clear magenta color. PREPARATION:The amino group of leucophenazine dye is protected with a arylaldehyde compound, acylated, the amino group at the 3- or 7-position is left and an acyl group containing an electron attractive substituent group is introduced to give a compound shown by formula I.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a dihydrophenazine compound that can be thermally stimulated in combination with an inorganic nitric acid or nitrite compound, or an organic salt of nitric acid, which can color the dihydrophenazine compound when heated. It is a useful thermally imageable compound that develops a bright magenta color by giving 1'')L.

[Conventional technology]

JP-A-59-198189 discloses naphthoylated dihydrophenazine compounds as thermographic materials.

This publication states that when an amine group is present at the 3- or 7-position, the amino group at the 3- or 7-position is also naphthoylated along with the 10-position during naphthoylation of the leuco compound. . JP-A-61-89259 relates to a thermal image-forming composition, and discloses a dihydrophenazine compound into which an acyl group having an electron-withdrawing substituent is introduced at the 10-position. This publication only describes a synthetic method in which the corresponding leuco form is directly acylated; if an a(': mino group is present at the 3- or 7-position, the amino group is Δ protected from acylation, British Patent No. 1271289 relates to a stabilized dihydrophenazine compound or phenoxazine compound, but this specification also does not take into consideration the presence of an amino group at the 3- or 7-position. In this case, 10-
JC does not take into consideration that the amino group at the 3- or 7-position is also acylated at the same time as the amino group at the 3- or 7-position.

Dihydrophenazine compounds that have an amino group at the 3- or 7-position have low stability against heat and light;
No synthesis example of a dihydrophenazine compound having an amino group at the 7-position or the 7-position has been reported.

[Problem that the invention seeks to solve]

Dihydrophenazine compounds, like phenoxazine compounds and phenothiazine compounds, are important as oxidative color-forming thermal image-forming compounds. Phenazine dyes having an amino group at the 3- or 7-position, such as 3-amino-7-diethylamino-5-phenylphenazonium chloride, have a magenta color that is preferred for forming color images. However, in the 10-acyl-5,10-dihydrophenazine compound obtained by reducing and directly acylating this phenazine dye, the amino group at the 3-position is also acylated, and the hue exhibited by oxidation is dark purple, which is preferable magenta. It cannot show color. In addition, 10-acyl-5, which has an amine group at the 3- or 7-position
The 10-dihydrophenazine compound is particularly unstable to heat and light among similar dihydrophenazine compounds, and it has been difficult to obtain it as a stable compound.

[Means for solving problems]

In order to obtain a 10-acyl-5,10-dihydrophenazine compound having an amine group at the 3- or 7-position using a phenazine dye as a raw material, the amino group at the 3- or 7-position must be protected from acylation. Must be. For this protection, it is commonly used as a protecting agent for primary amino groups.
After acylation using a raldehyde compound, the protecting group was removed with acid to regenerate the amino group. In addition, 10-acyl-5゜O having an amino group at the 3- or 7-position
- In order to stably obtain a dihydrophenazine compound, 10-
It was necessary to introduce an electron-withdrawing substituent to the acyl group at position.

That is, the present invention relates to a general formula (wherein R1 is an aryl group having an electron-withdrawing substituent or an alkyl group having an electron-withdrawing substituent) characterized by having an amino group at the 3-position or the 7-position. group, R1 and R6 are lower alkyl groups, R
3 is an aryl group which may have a substituent tA group, or an alkyl group which may have a substituent; R4 and R5 are each independently an aryl group which may have a W substituent, or a substituent; Indicates an optional lower alkyl group. ) provides a novel dihydrophenazine compound represented by:

10-acyl-5,10-dihydrophenazine compounds are less stable than corresponding phenoxazine and phenothiazine compounds, and are unstable to heat and light. In particular, compounds with an amino group at the 3- or 7-position have low stability, and unless a specific acyl group is introduced, the 10-
Acyl-5°10-dihydrophenazine compound cannot be obtained. The present inventors have demonstrated that even when an amine group is present at the 3- or 7-position, by inserting an acyl group having an electron-withdrawing substituent at the 10-position, a stable 1
Obtaining a 0-acyl-5,1o-dihydrophenazine compound and having an amino group at the 3-position or 7-position, the compound is used as an oxidative color-forming thermal image-forming compound to develop a preferable magenta color. They discovered this and arrived at the present invention.

The electron-withdrawing substituent includes the following. These include halogen atoms, trifluoromethyl groups, trichloromethyl groups, alkylcarbonyl groups, arylcarbonyl groups, cyano groups, nidotetra groups, alkylsulfonyl groups, arylsulfonyl groups, and the like.

10 having an amino group at the 3- or 7-position of the present invention
-Acyl-5,10-dihydrophenazine compounds can be produced by the following general method. The starting compound phenazine dye is dissolved in water by heating, and the leuco compound is dissolved and reduced under alkaline conditions with sodium hydrosulfide in the presence of a water-immiscible solvent such as 1,2-dichloroethane or toluene. After the reduction, a benzaldehyde derivative, for example, is added as a protecting agent for the weakly acidic amine group, and the amino group is converted into a benzalamino group. Then, in the presence or absence of an aqueous layer and in the presence of a deoxidizing agent, an acyl chloride having an electron-withdrawing substituent or a carboxylic acid anhydride having an electron-withdrawing substituent is added dropwise to effect acylation at the 10-position. Let's do it.

The layers are separated and the solvent layer is treated with dilute hydrochloric acid to remove the protective group and extract the product.The aqueous layer is separated, neutralized, and the precipitated crystals of the product are collected by filtration. The crude product is redissolved in a solvent such as toluene, and purified by repeated decolorization and recrystallization using silica gel or activated carbon for purification.

As a protecting agent for the amino group at the 3- or 7-position, aryl aldehyde compounds can be used, but among them, the azomethine compound produced is stabilized by hydrogen bonding with the hydroxyl group at the ○-position. Arylaldehyde compounds having groups are preferred. For example, salicylaldehyde, 5-chlorosalicylaldehyde, 3.5-dichlorosalicylaldehyde, 5-bromsalicylaldehyde, 3.5-dibromsalicylaldehyde, 5-nitrosalicylaldehyde, 3-nitrosalicylaldehyde, 0-vanillin ( 3-methoxysalicylaldehyde), 3-ethoxysalicylaldehyde, 2,
3-dihydroxybenzaldehyde, 2.4-dihydroxybenzaldehyde, 2.5-dihydroxybenzaldehyde, 2-hydroxy-1-naphthaldehyde, 1
-hydroxy-2-naphthaldehyde and the like. These protecting groups are easily removed by a conventional method such as treatment with dilute hydrochloric acid, and the amino group at the 3- or 7-position is regenerated.

Examples of the acylating agent include dichloroacetyl chloride having an electron-withdrawing substituent, trichloroacetyl chloride, tricloacetic anhydride, trianhydride, fluoroacetic acid,
2,4-dichlorobenzoyl chloride, 2-trifluoromethylbenzoyl chloride, 4-trifluoromethylbenzoyl chloride, 2-trichloromethylbenzoyl chloride, 4-trichloromethylbenzoyl chloride, 2-acetylbenzoyl chloride, 4-acetylbenzoyl chloride, 2-chlorocarbonylbenzophenone, 4-chlorocarbonylhensiphenone,
2-cyanohendiyl chloride, 4-cyanohendiyl chloride, 2-nitrohenzoyl chloride, 4
-Nitrohendiyl chloride, 4-methylsulfonylhendiyl chloride, 4-(P-tolylsulfonyl)
Hendiyl chloride and the like can be suitably used.

As detailed above, when a leucophenazine dye is directly acylated, if an amino group exists at the 3- or 7-position, the amino group at the 3- or 7-position is also acylated at the same time. By protecting the amino group with an aryl aldehyde compound and performing the acylation reaction, the amino group at the 3- or 7-position is left, and the stability of the product is improved by introducing an acyl group with an electron-withdrawing substituent. A 10-acyl-5,10-dihydrophenazine compound having an amino group at the 3- or 7-position can be obtained from a phenazine dye.

This 10-acyl-5,10-dihydrophenazine compound having an amino group at the 3-position or 7-position can be prepared using an inorganic nitric acid or nitrite compound, such as zinc nitrate, aluminum nitrate, which can cause the dihydrophenazine compound to develop a special color. ,
Cobalt nitrate, ferric nitrate, nickel nitrate, manganese nitrate, copper nitrate, lanthanum nitrate, nickel nitrite, cobalt potassium nitrite, cobalt ammonium nitrite, etc.? 1
It develops a vivid magenta color by applying thermal stimulation. The heat-sensitive coloring layer is obtained by dissolving the above-mentioned dihydrophenazine compound and an inorganic nitrate or rustite capable of causing the dihydrophenazine compound to develop a special color under heat, together with a binder, in a solvent that has solubility in these media. It can be prepared by applying a coating solution prepared on paper, synthetic paper, or heat-resistant film and drying it.

The binder is not particularly limited as long as it is compatible with the medium used. Further, the solvent may be any solvent as long as it has solubility, and is not particularly limited, but a polar solvent having high solubility for inorganic nitric acid or nitrite compounds is preferred. Furthermore, the present invention does not preclude the use of two or more types of leuco dyes or two or more types of inorganic nitric acid or nitrous acid compounds in the coating solution for preparing the heat-sensitive coloring layer.

Next, the present invention will be explained by examples. Note that the present invention is not limited to the following examples.

Example 1 3-amino-7-diethylamino-5-phenylphenazonium chloride, 18.9 g (0.05 mol)
was dissolved in 350 ml of hot water at 80°C. The mixture was cooled to 70°C and 350 ml of toluene was added. At 60°C, 43.5 g (0.25 mol) of sodium dithionite and 20 g (0.1 mol) of a 20% aqueous sodium hydroxide solution were added and stirred vigorously. Nitrogen gas was introduced into the reaction vessel, and after the color of the dye completely disappeared, 13 mj of glacial acetic acid! and adjust the pH to about 4.
And so. Salicylaldehyde 1,3 g (0,1
25 mol) was added dropwise at 60°C over 30 minutes. After stirring at the same temperature for 3 hours, it was cooled to room temperature and 9 g of sodium hydroxide (0,2
25 mol) was added. Next, 26.1 g (0,125 mol) of 2-trifluoromethylbenzoyl chloride
was added dropwise over 1 hour while maintaining the temperature at 20 to 30°C, and then stirred for 3 hours. At the end of the reaction, no excess 2-trifluoromethylbenzoyl chloride remained.

The reaction product was filtered, the filtrate was separated, and the toluene layer was diluted with IN hydrochloric acid 2.
50- was added and stirred for 30 minutes at 30-35°C for hydrolysis. The aqueous layer was separated and hydrolyzed again with 250% of IN hydrochloric acid. The aqueous hydrochloric acid layers were combined, washed with 25 mA of chloroform, neutralized with sodium hydroxide, and the precipitate deposited was extracted with 150 rd of toluene. After washing with the same amount of water, it was dried over anhydrous sodium sulfate and purified by adding activated carbon Log. Concentrate the toluene solution and dry it to obtain 17.6 g of yellow powder.
I got it.

This was recrystallized from a mixed solvent of 5Qml of n-octyl chloride and 200d of cyclohexane, and the melting point was 139.5.
~143.0°C pale yellow crystals 14.9g (yield 57.7
%) was obtained.

IR (Nujo I): NH23460,338
0, >Co 1640 cm-', 13C-NMR (C
DCβ3): 6144.8 (RiC-NH2S)16',
, 5 (>COS) λmax: 558 nm (95% acetic acid, photooxidation color development) Using the dihydrophenazine compound obtained as above, a coating liquid having the following composition was prepared.

This coating solution was coated onto the surface of high-quality paper using a wire bar so that the solid content after drying was 3 g/bo and dried to obtain heat-sensitive recording material No. 4.

Zinc nitrate/hexahydrate Log This heat-sensitive recording material was heated to a surface pressure of 0.
When heated at 4 kg/m at 170°C for 2 seconds, a clear reddish-purple color developed.

Example 2 Example 1 was carried out using the dihydrophenazine compound shown in Table 1 instead of the dihydrophenazine compound used in Example 1.
A coating solution similar to that described above was prepared to obtain heat-sensitive recording materials (a) to (c).

Table 1 When heat-sensitive recording materials (a) to (c) were heated for 2 seconds at 170° C. under a surface pressure of 0.4 kg/cd using a stamp coloring machine, they similarly developed a dull reddish-purple color.

Example 3 A coating solution having the following composition was prepared and applied to the surface of high-quality paper using a wire bar so that the solid content after drying was 2 g/ml and dried to obtain a heat-sensitive recording material.

This heat-sensitive recording material was processed using a stamp coloring machine under a surface pressure of 0.4 kg/
cut When heated at 160°C for 3 seconds, a clear reddish-purple color developed.

Control Example 1 18.9 g (0.05 mol) of 3-amino-7-diethylamino-5-phenylphenazonium chloride was dissolved in 350 ml of hot water at 80°C. It was cooled to 70°C and 350 ynl of toluene was added. At 60° C., 43.5 g (0.25 mol) of sodium dithionite and 20 g (0.1 mol) of a 20% aqueous sodium hydroxide solution were added and stirred vigorously. Nitrogen gas was introduced into the reaction vessel, and the mixture was stirred and cooled until the color of the dye completely disappeared. α at 20-30°C
-28.6 g (0.15 mol) of naphthoyl chloride was added dropwise over 30 minutes, followed by stirring for 30 minutes. After the reaction was completed, an aqueous sodium bicarbonate solution was added dropwise to decompose and neutralize excess α-naphthoyl chloride. The reaction mixture is separated,
It was washed with hot water and dried with anhydrous sodium sulfate. The toluene solution was decolorized and purified using activated carbon and silica gel for purification, and then concentrated. 200 ml of ethanol was added, and the mixture was heated to reflux for crystallization. The crystals were filtered, washed with ethanol, and dried to obtain 21.2 g (yield: 65.0%) of greenish-yellow crystals with a melting point of 244-247°C.

IR (Nujol):>NH3300,>C01660
, 1670 cm-', "C-NMR (CDC1z)
'δ 167.4 (>Co, S) 169 (>
C03S) This 3-(α-naphthoylamino)-5-phenyl-7
-dinithylamino-10-(α-naphthoyl)-5,1
0-dihydrophenazine was colored by photooxidation in 95% acetic acid and exhibited λmax of 548 nm and 580 nm.

Absorption maximum also occurred in the long wavelength range, and the hue changed to purple. Furthermore, the absorption was very broad due to two adjacent absorption maxima, and the color purity was greatly reduced. This dihydrophenazine compound, in which the amino group at the 3-position is also acylated, exhibits a considerable change in hue and cannot be used as the magenta color desired in forming color images.

Hodogaya Chemical Industry Co., Ltd.

Claims (1)

[Claims] General formulas characterized by having an amino group at the 3- or 7-position ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (I) (In the formula, R^1 is an electron-withdrawing substitution Aryl group having a group or alkyl group having an electron-withdrawing substituent, R^2
, R^6 is a lower alkyl group, R^3 is an aryl group which may have a substituent, or an alkyl group which may have a substituent, R^4 and R^5 are each independently a substituent. represents an aryl group which may have a substituent or a lower alkyl group which may have a substituent. ) dihydrophenazine compound.